Thermal insulation



April 3, 1962 G. E. GRONEMEYER 3,028,278

THERMAL INSULATION Original Filed July 13, 1954 3 Sheets-Sheet 1 7 INVENTOR val-7:, Z

April 1962 G. E. GRONEMEYER 3,028,278

THERMAL INSULATION 5 Sheets-Sheet 2 Original Filed July 13, 1954 April 1962 G. E. GRONEMEYER 3,028,278

THERMAL INSULATION Original Filed July 13, 1954 3 Sheets-Sheet 3 f f 45 f7; 9.

IN VENTOR ATTORNEY United States Patent 3,028,278 THERMAL INSULATION George E. Gronemeyer, Morrisville, Pa., assignor to Mirror Insulation Company, Inc., Lambertville, N.J., a corporation of Delaware Original application July 13, 1954, Ser. No. 443,033, now Patent No. 2,841,203, dated July 1, 1958. Divided and this application May 28, 1958, Ser. No. 738,342

Claims. (Cl. 154-45) This invention relates generally to thermal insulation such as is illustrated and described in Letters Patent of the United States No. 2,613,166, issued to me under date of October 7, 1952; the present invention aiming to materially improve the construction and assemblage of this particular type of installation to more adequately improve the insulation characteristics, to simplify the construction of the device as well as its method of application and maintenance in practice.

Thermal insulations of the prefabricated reflective type, such as disclosed in my above mentioned patent as well as in other constructions heretofore proposed, have certain disadvantages such as high price, inadequate life, lack of ruggedness suflicient for industrial use, cost in installation and maintenance as well as difliculty to remove, repair and/ or replace. An outsanding reason for physical failure of some forms of reflective insulation structures heretofore proposed has been lack of structural strength due to the use of certain non-conductor insulating type materials as structural elements. These tend to embrittle and weaken after exposure to heat for a period of time, resulting in defective installation where non-metal supports and spacer materials of this character have been used to separate and hold the reflective metal insulating sheets in place. A further reason for failure of such preyious reflective insulation is the lack of structural strength of the insulating unit as a whole, lack of sufficient rigidity of the reflective insulating and easing sheets of the insulating units, and lack of sturdiness of joints between panels or sections of insulation.

A still further reason for failure of certain other reflective insulations has been that provision has not been made for locking the joints of adjacent insulating units together, with the result that they open up and cause excessive heat loss. in service.

An object of the present invention is to provide an allmetal thermal insulation structure having hither-to unobtainable ruggedness, durability, lightweight, and high efliciency performance, which may be constructed and as- 'sembled at moderate cost with no dust, cement, broken 3,923,273 Fatented Apr. 3, 1962 This application is a division of my copending application Serial No. 443,033, filed July 13, 1954, now Patent No. 2,841,203, granted July 1, 1958, entitled Thermal Insulation.

With the foregoing objects in view, together with others which will appear as the description proceeds, the invention resides in the novel construction, combination and arrangement of parts, all as will be described more fully hereinafter, illustrated in the drawings and particularly pointed out in the claims.

In the drawings:

FIG. 1 is a fragmentary perspective view, parts broken away, disclosing one of the diaphragms for maintaining the spaced heat reflecting sheets around a curved section such as a pipe,

FIG. 1a is an enlarged fragmentary transverse sectional view illustrating the manner in which the diaphragm shown in FIG. 1 may be secured to the angle members,

FIG. 2 is a fragmentary sectional view taken through the longitudinal axis of a'pipe insulating unit disclosing a fabrication detail for attaching the diaphragms to the outer case or shell by means of lock seams,

FIG. 2a is a fragmentary sectional view showing an enlarged detail of one means developed for limiting the heat of flow from the diaphragms to the outer case of FIG. 2,

FIG. 2b is a similar view showing'a further modification of such connection,

FIG. 20 is a similar view of a further alternate construction,

FIG. 2d is an end elevation of the diaphragm portion shown in FIG. 20,

FIG. 3 is a plan view showing the same inventive idea carried out in flat surface insulation,

FIG. 4 is a side elevation of the structure shown in FIG. 3,

FIG. 5 is an enlarged detail sectional View taken substantially upon line 55 of FIG. 3,

FIG. 6 is a fragmentary enlarged elevational plan view showing the manner of connecting the ends of the spacers of FIG. 5,

FIG. 7 is a sectional view taken substantially upon line I 7 7 of FIG. 6,

refractory or similar mess involved in the use of the product.

A further object of the invention is to provide prefabricated self contained insulating units complete with weatherproof case and means for securing the units in place, the units to be of such size and construction as to be readily handled, facilitating ease of installation or removal or replacement.

' A further object of the invention is to provide a thermal insulation structure incapable of deterioration or becoming defective after prolonged exposures to severe service temperatures, or from expansion movements in service, which will be highly weather resistant, fireproof, as well as bacteria-proof and vermin-proof.

A still further object of the invention is to provide insulation of prefabricated type for hot and cold service requiring no special tools or skill for installation, composed of segments or panels entirely self contained, which may be assembled in proper relationship with respect to one another much more rapidly than other types heretofore proposed and which may with equal ease and facility be removed as occasion demands.

PEG. 8 is a plan view of the panel frarne, and

FIG. 9 is a side elevation of the frame shown in FIG. 8.

As will appear more fully hereinafter, heat insulation is normally used to insulate a surface having a temperature above the dewpoint of the surrounding atmosphere, whereas, cold insulation is normally used to insulate a surface having a temperature below the dewpoint, This invention is designed for heat, cold or both heat and cold insulations. When used for cold, the external casing joints are sealed in a conventional manner to prevent moisture infiltration. In referring to prefabricated units as involved in this invention, reference is made to prefabricated assembly of parts of each unit either at the source of manufacture or at the point of use, before mounting the unit on a surface to be insulated. One unit or panel of the various forms of insulation in the present invention may embody the use of a single sheet of heat reflective metal covering the surface being insulated, or a plurality of such sheets depending on the insulation efiiciency desired. These heat reflective metal sheets of a desired thickness are composed of aluminum, aluminum alloy, zinc alloy, stainless steel, or any metal having the property of high heat reflectivity and of selfsustaining character.

For heat or cold insulation, I employ support sheets of thin stainless steel to support and space the metal insulating sheets arranged transverse thereto. Such a support sheet has a thermal conductivity of roughly one hundred or more times that of-non-conductor or insulator type materials. However, it also has an even greater ratio of strength, toughness, and durability when exposed to heat. My design provides essential reenforcement for the thin support sheet and provides other features of construction herein described to limit th flow of heat through it.

For either heat or cold insulation, the very thin support sheets just described, are made into certain parts of the insulating structure which are referred to in the following as heads, diaphragms or split disks in the case of pipe or curved surface insulation, and as panel frame and channel spacers in the case of flat panel insulation.

Referring now more particularly to the drawings, FIGS. 1 to 2d inclusive, and FIGS. 3 to 9 inclusive, disclose my improved insulation structures applied to the insulation of pipes, curved surfaces and flat surfaces.

FIG. 1 of the drawing shows an arcuate diaphragm 10 of the type used in the application of my improved insulation structure to curved surfaces such as pipes or tanks; the inner edge of the diaphragm being arcuate as shown to correspond to the curvature of such surface,- while the outer edge 12 is concentric therewith. With reference to FIG. 2 it will be observed that these diaphragms 10 are arranged in spaced parallelism upon the pipe or other curved surface and spaced thin sheets of heat reflective material 13 such as aluminum sheets are arranged concentric with the surface of the pipe to be insulated and in spaced parallelism so as to provide closed pockets or air chambers between them. The ends of these heat reflective sheets are disposed in the spaces 14 between fingers 15 projecting inwardly from the edges of the diaphragms 10 in the manner fully illustrated, described and claimed in my parent application heretofore identified.

It is highly desirable to minimize the flow of heat by conductivity through the diaphragms 10 to the outer shell or wrapper, and with reference to FIG. la it will be observed that the diaphragm 10 is provided upon its inner surface with inwardly projecting bosses 16 of extremely limited area to provide a substantially knife-edge contact with the adjacent surface of the angle members 17; a rivet 18 of small diameter passing through the bosses 16 to secure the diaphragm to the angle members. Bosses of this character may be employed in any desired number. The angle members 17 and 19 are of heat conductive material and are of rigid construction in order to lend rigidity to the completed diaphragm assembly, and it will be observed that similar outer angle members 20 are also employed; the angle members 17 and 19 corresponding to the curvature of the inner and outer edges respectively of the diaphragms. FIG. la is a sectional view taken through the inner'edge of the diaphragm assembly, and illustrates that by reason of the bos and rivet arrangement above described, the diaphragm 10 is maintained in spaced relationship to the angle member yet is rigidly secured thereto, and the contact and securing means are of such limited area as to minimize the flow of heat from the angle member to the diaphragm, or vice versa. It will be understood that the outer angle member is connected in similar manner to the outer periphery of the diaphragm.

As shown in FIG. 1, the fingers 15 are integral with an angular plate or member 20' which is also secured to the straight edges of the diaphragm by means of rivets 18 in the same manner in which the arcuate angle members 17 and 19 are connected to the diaphragm. This arrangement minimizes the opportunity for the transmission of heat by conductivity between these elements.

With reference to FIG. 2 of the drawings, the insulation elements are shown in the position they will assume in surrounding a tubular structure such as a pipe or tank, and wherein there is a variation in the means for securing the diaphragms lit to the outer case or wrapper sheet 21. At the left of FIG. 2 there is shown a fold arrangement illustrated more clearly in the enlarged fragmentary section FIG. 2a. Here it will be observed, the outer case or wrapper sheet is bent or folded upon itself at its extremity to provide an annular socket 22 to receive the inwardly directed rim flange 23 of the diaphragm 10. After this rim flange has been inserted in the socket, the outer end 24 of the outer case or wrapper sheet is bent inwardly so as to enclose the outer circumference of the diaphragm 10 within the pocket thus formed in the end of the wrapper sheet. In order to minimize heat transfer from the diaphragm 10 to the wrapper sheet 21, the rim flange 23 and the adjacent edges of the diaphragm are provided with integral protuberances or beads 25 which engage in line contact with adjacent surfaces of the fold of the end of the outer case or wrapper sheet, at the same time assuring arigid connection between these parts.

The opposite end of the structure shown in FIG. 2 is so constructed as to interfit with a companion tubular insulating section of similar character, and to this end the fold of the wrapper sheet indicated at 26 is disposed inwardly from the extremity of the wrapper sheet to provide a recess 27 into which the adjacent end of a companion insulating section may engage. The adjacent diaphragm 10 will be formed similarly to that at the opposite end of the insulating section and a pin or other fastener 28 of small compass may be passed through the wrapper sheet as well as through the inturned end of the diaphragm extremity, in order to secure the diapnragm to the wrapper sheet.

FIG. 2b of the drawing shows a slight modification of the connection between the diaphragm flange and the end of the outer or wrapper sheet. In this instance, the inwardly projecting. flange 29 of the diaphragm 10 is provided at its extremity with a rolled portion 30 which provides line contacts between the flange and the wrapper sheet fold and holds the flange in spaced relationship to the surfaces of these folds. Moreover, the outer extremity of the diaphragm is rolled or formed so as to provide annular oifset portions 31 to engage with adjacent parts of the folded end of the wrapper sheet as well as the inwardly projecting flange 32 at the end thereof. This structure brings about a firm connectionbetween the diaphragm and the end of the wrapper sheet and at the same time provides line contact between these elements to thus prevent heat transfer by conduction.

FIGS. 20 and 2d of the drawing show the same inventive idea in a slightly varied form, wherein the outer surface of the inwardly directed flange 33 of the diaphragm 10 is provided with a series of projections 33 formed preferably by the well known crimp process, in order to provide line contact elements between the flange and the adjacent surfaces of the wrapper sheet fold. Similarly, the outer periphery of the diaphragm 10 is provided with radially disposed crimps 34 to bring about a series of line contacts between the diaphragm and the adjacent portions of the wrapper end.

It is obvious that the structures disclosed in FIGS. 2 to 2d inclusivecan equally as well be employed in instances where the diaphragm 10 is provided with arcuate angle members 17 and 19 as disclosed in FIGS. 1 and 1a of the drawings.

FIGS. 3 to 9 inclusive show the same inventive idea carried out as flat surface insulation. This insulating unit may be referred to as a flat panel composed of a plurality of heat reflective thin metal insulating sheets, including an outer case 35, an inner case 36, a panel frame 37 and a plurality of inner liners 38 maintained in spaced parallelism within the panel to provide the spaced insulating air pockets extending the full length and breadth of the panel. The outer case 35 is attached to the top flange of the frame 37 by suitable fasteners 39 through holes 3911 provided in frame 37 and it-will beobserved that the edges of the outer case are provided with downturned flanges 40 to overlie the frame 3 7 and reenforce the outer case. It will be observed that the panel frame 37 completely encloses the inner liner sheets 38 and the inner case 36, the said sheets 38 being spaced or separated from each other by channel spacers indicated at 41 at the periphery of each sheet. These channel spacers in cross section are in substantially the shape of an inverted M, the crowns of which rest upon a sheet and the legs of which in turn support the next overlying sheet as shown more particularly in FIG. of the drawings. These spacers are held in parallel alignment with the outer case 35 by means of pins 42 which pass through suitable openings provided in the outer case frame, inner case, and in the several channel spacers 41. These pins sandwich the sheets and channels firmly together and assist in maintaining a rigid assembly. The lower ends of these pins 42 are secured by fasteners 43. To provide for internal expansion and contraction, the inner sheets 38 and 36 are so cut as to provide edge clearance between each sheet and the inside surface of the panel frame as shown more particularly in FIG. 5 of the drawing. The inner case 36 is further secured to the frame 37 by spring angle clips 44 and fasteners 45, the outer end of each of said clips being enclosed in the folded portion 46 at the lower end of the frame 37. Holes 47 are provided along the lap extensions of the outer case 35 for the insertion of installation fasteners (not shown) such as sheet metal screws. The sides of the panel frame may also be provided with knock-out holes 48 to enable wires to be inserted in the holes thus provided and the unit secured to lugs, rods or other means of attachment on the surface being insulated.

The detail view, FIG. 5, also illustrates the means here employed of limiting heat flow between high conductivity metal parts by restricting the contact beween such parts to substantially line contact, plus the minute contact through small fasteners. A single continuous bead 49 is formed on the side and end faces of the panel frame to engage the depending flange 40 of the outer case, and continuous beads 50 are formed on all top flanges of the panel frame to provide said line contact, structural support, and convection seal between these parts. This same construction of line contact, support and seal is used for the channel spacers 41 which are constructed in substantially inverted M form, as shown, and serve these functions with respect to the inner case 36, insulating sheets 38 and top flange of frame 37.

FIGS. 6 and 7 show one course of the specially formed end channel and side channel spacers, showing in particular the fin-type corner lock 51 between channels, while FIGS. 8 and 9 are top plan and side elevational views respectively of the panel frame.

In all the designs covered by this invention, the outer case normally is a heat reflective metal insulating sheet, but in special instances it may consist of any other metal or plastic in order to meet corrosive or other unusual conditions. Outstanding advantages of the invention are that it offers to industry a thermal insulation product fabricated in units for rapid low cost installation on pipes, curved surfaces and fiat surfaces, and the units may be available in all metal construction to offer a product of hitherto unobtainable ruggedness, durability, lightweight, high efiiciency performance, weather resistance, and thermal shock resistance, at moderate cost. The manner in which these units are constructed and assembled produces great tensile strength, and enables the units to be applied to the surface to be insulated by simple methods, thus economizing time and cost of field installation without the sacrifice of ruggedness or insulation efficiency. Moreover, the manner in which the various sections are secured together, both transversely as well as longitudinally of the surface to be insulated, insures positive locking of all joints in such manner as to minimize the opportunity for heat loss at the joints.

I claim:

1. In a weatherproof reflective metal insulation structure, a panel frame of relatively thin heat conductive metal providing upstanding side and end walls in spaced parallelism, said side and end walls having each a top horizontally directed flange projecting inwardly from the upper edges thereof and at substantially right angles thereto, a plurality of sheets of heat reflective metal disposed within said panel frame in spaced parallelism with one another and to said top flanges to provide dead air spaces between them, means at the marginal edges and independent of and spaced from said frame to space and support the ends of said sheets in line contact, a cover plate overlying said frame and said sheets, beads projecting outwardly from said flanges to engage said cover plate in line contact, and means for securing said cover plate, frame, reflective metal sheets and spacer members in assembled relationship.

2. A weatherproof reflective metal insulation structure as defined in claim 1, wherein the means for securing the parts in assembled relationship are pins.

3. A weatherproof reflective metal insulation structure as defined in claim 1, wherein the means at the marginal edges constitute metal spacer members of substantially M-shape cross section.

4. A weatherproof reflective metal insulation structure as defined in claim 1, wherein such structure is applicable to a flat surface.

5. A weatherproof reflective metal insulation structure as defined in claim 1, the lowermost of the reflective sheets being secured to the frame by spring angle clips and fas teners at each end thereof, the outer end of each clip being enclosed in a folded portion at the lower edge of the frame.

References Cited in the file of this patent UNITED STATES PATENTS 1,984,007 Babbitt Dec. 11, 1934 2,050,663 Le Grand Aug. 11, 1936 2,122,453 Clause July 5, 1938 2,578,600 Rose Dec. 11, 1951 2,613,166 Gronemeyer Oct. 7, 1952 2,841,203 Gronemeyer July 1, 1958 FOREIGN PATENTS 508,731 Germany Oct. 1, 1930 

1. IN A WEATHERPROOF REFLECTIVE METAL INSULATION STRUCTURE, A PANEL FRAME OF RELATIVELY THIN HEAT CONDUCTIVE METAL PROVIDING UPSTANDING SIDE AND END WALLS IN SPACED PARALLELISM, SAID SIDE AND END WALLS HAVING EACH A TOP HORIZONTALLY DIRECTED FLANGE PROJECTING INWARDLY FROM THE UPPER EDGES THEREOF AND AT SUBSTANTIALLY RIGHT ANGLES THERETO, A PLURALITY OF SHEETS OF HEAT REFLECTIVE METAL DISPOSED WITHIN SAID PANEL FRAME IN SPACED PARALLELISM WITH ONE ANOTHER AND TO SAID TOP FLANGES TO PROVIDE DEAD AIR SPACES BETWEEN THEM, MEANS AT THE MARGINAL EDGES AND INDEPENDENT OF AND SPACED FROM SAID FRAME TO SPACE AND SUPPORT THE ENDS OF SAID SHEETS IN LINE CONTACT, A COVER PLATE OVERLYING SAID FRAME AND SAID SHEETS, BEADS PROJECTING OUTWARDLY FROM SAID FLANGES TO ENGAGE SAID COVER PLATE IN LINE CONTACT, AND MEANS FOR SECURING SAID COVER PLATE, FRAME, REFLECTIVE METAL SHEETS AND SPACER MEMBERS IN ASSEMBLED RELATIONSHIP. 